Role of oxidative stress,angiogenesis and chemo-attractant cytokines in the pathogenesis of ischaemic protection induced by remote ischaemic conditioning: Study of a human model of ischaemia-reperfusion induced vascular injury

Aims

We explored the effect of remote ischaemic conditioning (RIC) on endothelial function and on circulating mediators.

VEGF基因特异性siRNA转染后对人乳腺癌细胞增殖和凋亡的影响

目的：探讨利用干扰RNA（RNAi）抑制血管内皮生长因子（VEGF）基因表达对乳腺癌细胞MCF-7增殖和凋亡的影响。方法：设计针对VEGF基因的小干扰RNA（siRNA）,合成DNA模板,体外转录siRNA。以脂质体转染法将双链siRNA导入MCF-7细胞后,用MTT比色法检测siRNA对MCF-7细胞增殖的影响。通过Hoechst33258染色观察MCF-7细胞的凋亡。用流式细胞术检测细胞周期的改变,RT-PCR检测VEGF mRNA表达的变化,免疫细胞化学法检测VEGF蛋白的表达。结果：所设计的两个靶位点siRNA,均能有效地抑制MCF-7细胞的增殖,诱导细胞凋亡,使细胞周期阻滞于G0/G1期,VEGFmRNA及其蛋白的表达明显减少;而作为阴性对照的错义序列组siRNASCR则没有上述效应。结论：体外转录合成的siRNA可抑制MCF-7细胞中VEGF基因的表达,抑制细胞增殖,促进细胞凋亡。     

Vascular endothelial growth factor and neo-angiogenesis in H. pylori gastritis in humans

Host response plays a major role in the pathogenesis of Helicobacter pylori-induced gastroduodenal disease including adenocarcinoma of the distal stomach. Vascular endothelial growth factor (VEGF) is an important modulator of gastric mucosal repair and is overexpressed in gastric cancer. The present study sought to evaluate the expression of VEGF in the gastric mucosa of H. pylori-infected and H. pylori-non-infected dyspeptic patients. Fifteen H. pylori-infected and 15 H. pylori-non-infected dyspeptic patients were studied. Diagnosis of H. pylori infection was based on rapid urease test and histology. VEGF protein expression was assessed by western blotting. VEGF mRNA expression was assessed by RT-PCR. VEGF localization in the gastric mucosa and neo-angiogenesis were determined by immunohistochemistry. VEGF protein and mRNA expression was significantly greater in H. pylori-infected than in non-infected patients. Immunohistochemistry showed that VEGF expression was more intense in the gastric gland compartment of H. pylori-infected mucosa than in the non-infected mucosa. The increase in VEGF expression was associated with a significant increase in neo-angiogenesis as assessed by determination of CD34-positive micro-vessels. H. pylori gastritis is therefore associated with up-regulation of VEGF expression, which parallels the increased formation of blood vessels in the gastric mucosa. It is postulated that increased VEGF expression and neo-angiogenesis may contribute to H. pylori-related gastric carcinogenesis.     

Cell biology and pathology of liver sinusoidal endothelial cells

Growing evidence revealed that liver sinusoidal endothelial cells (SEC) play several important roles in physiology and pathology of the liver. It has been well understood that their structural characteristics, such as the membrane sieve and lack of basement membrane, facilitate direct contact of soluble and insoluble serum substances with hepatic parenchymal cells, resulting in enhancement of hepatic metabolic activity. In addition, SEC is now regarded as a member of the scavenger endothelial cells, which have potential to eliminate a variety of macromolecules from the blood circulation by receptor-mediated endocytosis. It is reported that molecules preferentially eliminated by SEC are denatured or modified proteins such as advanced glycation end products, extracellular matrix components including hyaluronic acid, and some lipoproteins. The nature of the scavenger receptors corresponding to these molecules remains to be clarified. Recently, it was noted that SEC has an antigen-presenting function similar to dendritic cells. Taken together, it is suggested that SEC, cooperating with Kupffer cells and hepatic dendritic cells, may partake of immunoregulatory functions in the liver. SEC also plays a pivotal role in the pathological process of ischemia-reperfusion injury following liver surgery and liver transplantation. Thus, it is of importance to elucidate the mechanisms of apoptosis and proliferation of SEC. Recent results on the regulation of growth and apoptotic signaling of SEC are discussed.     

西藏大骨节病患者血清Se与几种细胞因子含量的变化

目的:测定大骨节病患者和正常对照血清中硒和肿瘤坏死因子-α(TNF-α)、血管内皮生长因子(VEGF)和白介素-1(IL-1β)的水平。从细胞因子角度为研究其发病机制提供实验依据。方法:在西藏拉萨尼木县和墨竹工卡县的大骨节病区随机选取大骨节病患者30例(患者组),病区正常人30例(病区内对照组),在拉萨非大骨节病区选健康志愿者30例(病区外对照组),3组人群年龄和性别没有显著性差异。采取静脉血离心制备血清。采用荧光法测定血清Se,酶联免疫吸附测定法(ELISA)检测血清中细胞因子水平。结果:西藏大骨节病病区患者和正常人血清中Se低于非大骨节病区正常人;患者血清中TNF-α、VEGF和IL-1β的水平高于正常。血清Se与TNF-α、IL-1β水平呈负相关趋势。结论:低硒和血清中细胞因子水平升高在KBD的发病过程中起着某种作用。     

Gene therapy of amyotrophic lateral sclerosis

Two-year experiments were performed to evaluate the neurotrophic effect of hypoxia-inducible factors (vascular endothelial growth factor and angiogenin) expressed in recombinant human adenoviruses in amyotrophic lateral sclerosis. Randomized placebo-controlled trial demonstrated safety and good tolerability of the recombinant antiviral drugs. The life span of patients under conditions of hypoxia increased after treatment with the test drug, which was probably related to improved resistance of motoneurons. The presence of virus-neutralizing antibodies decreases the effectiveness of adenoviral vectors, which necessitates differential approach to the selection of patients and continuous monitoring of gene therapy. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 4, pp. 467–470, April, 2008     

血管内皮生长因子受体在鼠横纹肌的表达与羟基磷灰石/碳纳米管复合材料毒性研究

目的 从观察鼠骨骼肌组织形态学改变和VEGF表达的角度研究CNTs/HAP纳微米复合材料对鼠骨骼肌的细胞毒性。方法 将CNTs/HAP纳米复合材料植入实验鼠臀大肌。按不同时间取材，做组织学观察和RT-PCR分析。结果 1d、3d显微镜下观察，炎细胞和淋巴细胞浸润伴轻度水肿、间质疏松；5d、7d显微镜下观察血管壁增厚，单核巨噬细胞和纤维组织增生，少量肌纤维出现变性，VEGF表达呈上升趋势；14天显微镜下观察周围组织间质血管扩张，仅有少量炎细胞浸润，水肿不明显，VEGF表达呈下降趋势。结论 CNTs/HAP对鼠骨骼肌细胞无毒性，有利于血管的再生，具有良好的生物相容性。     

VEGF真核表达载体的构建及在内皮与心肌细胞内的表达

目的：探讨外源性人VEGF165基因在内皮细胞与心肌细胞内表达的可行性。方法：构建了(vaseular endothelium growth factor,VEGF)与增强型绿色荧光蛋白(enhanced green fluorescent protein，EGFP)基因其表达载体pIRES2—FGFP—VEGF165，以脂质体法转染内皮细胞和心肌细胞，采用荧光显做镜检测内皮细胞与心肌细胞中EGFP的表达，同时利用免疫组织化学方法检测VEGF的表达。结果：成功地构建了真核表达载体pIRES2—EGFP—hVEGF165，采用脂质体法转染内皮细胞与心肌细胞后，经荧光显微镜观察，可见细胞内有EGFP的表达，同时经免疫组化证实有VEGF的表达。结论：采用脂质体法可以成功地将外源性VEGF165基因转染到内皮细胞与心肌细胞中，并进行表达。本研究为今后利用VEGF基因治疗心肌缺血等疾病提供了实验基础。     

A Subset of Type I Conventional Dendritic Cells Controls Cutaneous Bacterial Infections through VEGFα-Mediated Recruitment of Neutrophils

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